Study: Crocodiles Evolved From Warm-Blooded to Cold-Blooded Ancestors

In the long chronicle of life's adaptation, crocodiles have offered scientists a rare and humbling correction: evolution does not always climb. New research reveals that these ancient hunters descended from warm-blooded ancestors, voluntarily — in the language of natural selection — surrendering the metabolic machinery of endothermy for the lean patience of cold-blooded existence. The finding challenges the assumption that metabolic complexity moves in only one direction, suggesting instead that survival has always been less about progress and more about fit.